Flowable adhesives are typically supplied in a container (e.g., a tube) fitted with a nozzle. In use, adhesive flows from the container through the nozzle and is applied to an intended substrate. In the case of reactive adhesives, the adhesive has a tendency to cure in the nozzle causing it to clog. Moreover, in the case of flowable adhesives, there is often a tendency of the adhesive to drip or ooze (e.g., depending on its viscosity) from the nozzle between applications.
To overcome the problem of dripping or oozing, valves have been placed within the nozzle. Many valves in commercial use have multiple machined or cast metallic parts and are costly. Valves of this type can easily become inoperative due to the properties of the adhesive used. Due to their cost, much effort is put into keeping these valves (and hence nozzles) operational, especially when using curing/drying adhesives.
One known approach to overcoming the foregoing problems is embodied in the prior art nozzle useful for dispensing some flowable adhesives shown in FIGS. 1A and 1B. Referring now to FIGS. 1A and 1B, prior art nozzle 100 has a hollow body 105 made of polypropylene. An internal wall surface 110 defines a tubular conduit 120, which extends from an inlet port 145 to a dispensing port 140. Internal wall surface 110 has a cylindrical portion 112 adjacent a frustoconical portion 118. A vinyl resilient cap 150 snugly contacts frustoconical portion 118 of internal wall surface 110. The vinyl resilient cap 150 has an annular sidewall 160 extending from a circular base 170 that has a slit 180 therein. Prior art nozzle 100 also has screw threads 132 formed in the internal wall surface 110 adjacent inlet port 145, flange 134 proximate inlet port 145, and reinforcing ribs 107 formed on an exterior surface of the nozzle 100.